/*
 * Copyright 2009-2011 Cedric Priscal
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <termios.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <jni.h>

#include "SerialPort.h"

#include "android/log.h"
static const char *TAG="serial_port";
#define LOGI(fmt, args...) __android_log_print(ANDROID_LOG_INFO,  TAG, fmt, ##args)
#define LOGD(fmt, args...) __android_log_print(ANDROID_LOG_DEBUG, TAG, fmt, ##args)
#define LOGE(fmt, args...) __android_log_print(ANDROID_LOG_ERROR, TAG, fmt, ##args)

static speed_t getBaudrate(jint baudrate)
{
  switch(baudrate) {
  case 0: return B0;
  case 50: return B50;
  case 75: return B75;
  case 110: return B110;
  case 134: return B134;
  case 150: return B150;
  case 200: return B200;
  case 300: return B300;
  case 600: return B600;
  case 1200: return B1200;
  case 1800: return B1800;
  case 2400: return B2400;
  case 4800: return B4800;
  case 9600: return B9600;
  case 19200: return B19200;
  case 38400: return B38400;
  case 57600: return B57600;
  case 115200: return B115200;
  case 230400: return B230400;
  case 460800: return B460800;
  case 500000: return B500000;
  case 576000: return B576000;
  case 921600: return B921600;
  case 1000000: return B1000000;
  case 1152000: return B1152000;
  case 1500000: return B1500000;
  case 2000000: return B2000000;
  case 2500000: return B2500000;
  case 3000000: return B3000000;
  case 3500000: return B3500000;
  case 4000000: return B4000000;
  default: return -1;
  }
}

/*
 * Class:     android_serialport_SerialPort
 * Method:    open
 * Signature: (Ljava/lang/String;II)Ljava/io/FileDescriptor;
 */
JNIEXPORT jobject JNICALL Java_android_serialport_SerialPort_open
  (JNIEnv *env, jclass thiz, jstring path, jint baudrate, jint flags)
{
  int fd;
  speed_t speed;
  jobject mFileDescriptor;

  /* Check arguments */
  {
    speed = getBaudrate(baudrate);
    if (speed == -1) {
      /* TODO: throw an exception */
      LOGE("Invalid baudrate");
      return NULL;
    }
  }

  /* Opening device */
  {
    jboolean iscopy;
    const char *path_utf = (*env)->GetStringUTFChars(env, path, &iscopy);
    LOGD("Opening serial port %s with flags 0x%x", path_utf, O_RDWR | flags);
    fd = open(path_utf, O_RDWR | flags);
    LOGD("open() fd = %d", fd);
    (*env)->ReleaseStringUTFChars(env, path, path_utf);
    if (fd == -1)
    {
      /* Throw an exception */
      LOGE("Cannot open port");
      /* TODO: throw an exception */
      return NULL;
    }
  }

  /* Configure device */
  {
    struct termios cfg;
    LOGD("Configuring serial port");
    if (tcgetattr(fd, &cfg))
    {
      LOGE("tcgetattr() failed abcd errno = %s", strerror(errno));
      close(fd);
      /* TODO: throw an exception */
      return NULL;
    }

    cfmakeraw(&cfg);
    cfsetispeed(&cfg, speed);
    cfsetospeed(&cfg, speed);

    if (tcsetattr(fd, TCSANOW, &cfg))
    {
      LOGE("tcsetattr() failed");
      close(fd);
      /* TODO: throw an exception */
      return NULL;
    }

  }

  /* Create a corresponding file descriptor */
  {
    jclass cFileDescriptor = (*env)->FindClass(env, "java/io/FileDescriptor");
    jmethodID iFileDescriptor = (*env)->GetMethodID(env, cFileDescriptor, "<init>", "()V");
    jfieldID descriptorID = (*env)->GetFieldID(env, cFileDescriptor, "descriptor", "I");
    mFileDescriptor = (*env)->NewObject(env, cFileDescriptor, iFileDescriptor);
    (*env)->SetIntField(env, mFileDescriptor, descriptorID, (jint)fd);
  }

  return mFileDescriptor;
}

/*
 * Class:     cedric_serial_SerialPort
 * Method:    close
 * Signature: ()V
 */
JNIEXPORT void JNICALL Java_android_serialport_SerialPort_close
  (JNIEnv *env, jobject thiz)
{
  jclass SerialPortClass = (*env)->GetObjectClass(env, thiz);
  jclass FileDescriptorClass = (*env)->FindClass(env, "java/io/FileDescriptor");

  jfieldID mFdID = (*env)->GetFieldID(env, SerialPortClass, "mFd", "Ljava/io/FileDescriptor;");
  jfieldID descriptorID = (*env)->GetFieldID(env, FileDescriptorClass, "descriptor", "I");

  jobject mFd = (*env)->GetObjectField(env, thiz, mFdID);
  jint descriptor = (*env)->GetIntField(env, mFd, descriptorID);

  LOGD("close(fd = %d)", descriptor);
  close(descriptor);
}

